flux-core with gas ?

[SuperchargedS10]

on a car forum, a guy welded a differential with flux-core and c25. the weld looked really nice.

can i get some info on this ?

[Tankee]

It's called dual shield. Primarily it is used for application that require deeper penatration and as stated in another post, you need a bigger machine to run it properly. It does produce not only a deep penatration weld but also (in my opinion) a weld that is far better looking than hardwire.

For the average guy @ home I think the best weld process would be a stick welder and 7018 rod. It is failry easy to run an has excellent penatration. One main key to cast is the cooling process. Don't let it cool to quickly. If you wrap the peice up in a insulated fire blanket and let it slow cool.

As I said beforeand stated by others, I haven't seen a 180 or 200 class welder that can really run dual shield properly.

[SuperchargedS10]

iirc, the guy said he was using a 135 type machine. and made multiple passes to build it up.

thanx for the cooling tip.

i'm going to try it with my 135 machine to see what happens.

[klsm54]

Welding where a high strength weld is needed is not a job for a 110 volt welder with flux-cored wire. I am not doubting that someone has welded a differential with such a set-up and had some kind of success, just not recommending the process.

.030 wire is not available in a high strength dual shield type of wire and a 110 machine is extremely lacking in amps and OCV to weld with .035 wire of this type. Adding a cover gas to a 71T-GS wire is not going to magically add strength or impact resistance to this material. Over and above the lack of physical properties of flux cored wires available to weld in a 110 machine, there is the lack of penetration with the low amps and volts available.

If I absolutely had to make this type of weld with a 110 volt mig machine, it would be with solid wire and the area I was welding would be well vee'd out to make sure I was getting enough penetration.

Also you say the weld "looked" good. Looking good does not necessarily make the weld strong enough to stand the stresses put on it in an automotive application such as this.

[SuperchargedS10]

the welding was done to "add" strenght. not to joint to parts. the the tubes to the center section.